2 Invoking GPG-AGENT

gpg-agent is a daemon to manage secret (private) keys
independently from any protocol. It is used as a backend for
gpg and gpgsm as well as for a couple of other
utilities.

The agent is automatically started on demand by gpg,
gpgsm, gpgconf, or gpg-connect-agent.
Thus there is no reason to start it manually. In case you want to use
the included Secure Shell Agent you may start the agent using:

gpg-connect-agent /bye

You should always add the following lines to your .bashrc or
whatever initialization file is used for all shell invocations:

GPG_TTY=$(tty)
export GPG_TTY

It is important that this environment variable always reflects the
output of the tty command. For W32 systems this option is not
required.

Please make sure that a proper pinentry program has been installed
under the default filename (which is system dependent) or use the
option pinentry-program to specify the full name of that program.
It is often useful to install a symbolic link from the actual used
pinentry (e.g. /usr/bin/pinentry-gtk) to the expected
one (e.g. /usr/bin/pinentry).